If you are going to claim to build a limited edition car and this is a major selling point, keep it limited. An additional 103 M4 GTS models being produced is not some huge amount but it certainly means you can not believe BMW's marketing material.
BMW stated there would not be more than 700 M4 GTS vehicles produced. Whoops. A big whoops if you happened to be one of the people dealers took advantage of by putting a huge markup on the car under the guise of it being limited to only 700 models. It certainly will be interesting to see if anyone who paid over sticker makes a big deal about this.
There are now over 800 cars according to the VIN numbers with some extra 27 for promotional purposes such as magazine comparisons and car shows.
The bottom line? Don't trust BMW's marketing.
Source

Remember Forgeline announcing their Carbon+Forged wheels last week? Well, they are going to cost you $4k per wheel. Ok, to be accurate a 20 inch wheel starts at $3850 but you might as well round up. A set of these after taxes, tires, and mounting is going to run almost $20k.
Who is going to buy these? Is there a market, sure. However, it's not going to be your average enthusiast when a set with tires might cost more than what their whole car is worth.
Forgeline also did not provide any weights. If someone is going to pony up this kind of coin for a carbon barrel wheel they want to know what it weighs or else what are they paying for?
If interested, start saving now.
Cutting-Edge Directional Split-Five Spoke Center Machined From 6061-T6 Forged Aluminum
Thickly-Scuplted Angular Spokes
"Wrapped" Lug Holes
Thick Chamfered Spoke Bases That Alternate Along the Rim Register
Revolutionary Proprietary Carbon Fiber Barrel
Lightweight
Low Rotational Inertia
Minimal Deflection
Excellent Fatigue Strength
Carbon+Forged Carbon Fiber Barrel Exceeds All Existing SAE and TUV Test Specifications
Carbon+Forged Carbon Fiber Barrel Surpasses the AK-LH 08 Radial Impact Test Standard
Intended for Street Use. Not Recommended for Track Applications.
Available in 20 and 21-inch Fitments
Customizable Finish Options (Aluminum Center Only)
Carbon+Forged Carbon Fiber Barrel Finished in High-Gloss Natural Carbon Weave
Legendary Forgeline Quality and Customer Service

It is nice that there will be another option in the sport sedan sector to challenge the BMW M3, Mercedes-AMG C63, and Cadillac ATS-V. Alfa Romeo is bringing Italian style and performance to the market but it comes at $73,595 which puts it above the competition save for the C63 S.
Is it worth the money? 505 horsepower and 443 lb-ft of torque are stout numbers but we will reserve judgement until we see a dyno. The claimed 7:32 Nurburgring laptime is also very impressive although they did not back it up with any proof. They originally claimed a 7:39 time also with no proof.
This is poised to be a fantastic driver's car with the manual but the US will not get that option. We will instead get an 8-speed automatic. Maybe Alfa will with later models provide a manual but it certainly is a disappointment.
We will all learn soon enough how the car really stacks up to the competition.

Road and Track compared several of the new 2017 991.2 generation Porsche 911 models along with the 2016 911 GT3 RS. It is always interesting to see how many variants of the 911 platform Porsche has and how they stack up especially with the Carrera now being turbocharged.
So what is the best choice of this group? The answer to that is likely the one you can afford. The greatest value is the standard Carrera, no question. They tested a 7-speed manual version and it is a good value at $97k in this company and also the lightest of the group at 3229 pounds. Yes, even lighter than the GT3 RS.
Weights (lbs.):
3229 - 2017 991.2 Carrera manual
3292 - 2016 GT3 RS
3510 - 2017 Carrera 4S
3514 - 2017 Carrera S Cabriolet
3563 - 2017 911 Turbo S
If you opt for all wheel drive in a 911 the penalty is close to 300 pounds. The heaviest combo would be an all wheel drive convertible but they did not test this. The Turbo S is the heaviest car out of the group and a Turbo S convertible would likely be the heaviest 911 for sale.
Still, you can have your 911 is basically any flavor. If you want a lightweight and rear wheel drive 911 the Carrera fits the bill. It's pretty quick too. Note that the PDK Would be much quicker and faster than the manual:
1/4 mile times:
12.4 @ 114.9 is not bad at all. Especially considering the PDK version will run 11.9 @ 118. The Carrera 4S is offering 997.1 generation 911 Turbo performance which is incredible. With a couple upgrades it will be right on the tail of the drag race champ which of course is the 911 Turbo S.
With the 991.2 Porsche gave the Turbo S different, bigger turbochargers and you see the dividends in the performance numbers. The GT3 RS is surprisingly not far off the trap speed despite less power, torque, and the rear wheel drive layout.
The GT3 RS is obviously the top choice for someone who wants the closest thing to a 911 race car for the street. It is also incredibly expensive and will be replaced soon with the 991.2 generation car.
So which is truly the best of this group? For the dollar, it's impossible to beat the Carrera. Is the Turbo S really $100k better than the Carrera or Carrera S? No way. Road and Track picks the Turbo S as the choice of the group but when you're spending imaginary money why not just say the 918 Spyder is the car to get in the Porsche lineup?
All of these are fantastic cars. There is no loser. The choice is simply what is best for you and your bank account.

An 'S' designation for a 911 Turbo usually means a hardware differentiation over the standard Turbo. For example, the Porsche 996 Turbo S included the X50 package with larger K24 turbos over the standard 911 Turbo with K16 turbos. This meant the S version not only was faster stock but also gained more power with a tune.
With the 991.1 Turbo generation Porsche gave the 911 Turbo and the 911 Turbo S the same turbochargers. Why? Well, it saves money for one. However, the 991.1 Turbo S showed inconsistent performance.
Testing from Cobb showed the ECU pulling timing and cutting power. As a matter of fact, the 991.1 Turbo S with bolt on modifications could not match the 997.2 in performance with similar mods.
The 991.2 generation Turbo S changes all of this as it is performing like a tuned 991.1 Turbo S out of the box. Over 130 mile per hour in the 1/4 mile and low 10 second passes. This is an easy 9 second car with a tune.
The new turbochargers with larger impellers, revised cylinder heads, and new tune are making a huge difference. Expect 9's at over 135 miles per hour with bolt ons. In other words, actually getting your money's worth for the S model.

A long time ago Hamann was a respected BMW tuner. Now? They are a joke. Why? Because their 'tuning' consists of body kits and wheels. Hamann is the ultimate sellout. They realized long ago why should they bother doing any actual tuning work when spoilers and wheels require far less effort and generate far more profit?
If you are someone out there who wants teal wheels on your M2 by all means call up Hamann. What is the tuning here? A front lip, side skirts, a spoiler, and wheels that will actually slow the car down?
Hamann claims to bump the car up to 420 horsepower and 390 lb-ft of torque which should offset the performance lost by the increased drag and heavier wheels but of course does not provide a dyno to support any of their claims. That is what a company posing a tuner does.
Hamann is nothing more than someone who rebrands springs and offers cosmetic upgrades. If you want serious tuning for your M2, look elsewhere.

In case you needed more convincing that the 991.2 Turbo S is the real deal here you go. The R8 V10 Plus is no slouch but it simply is not a match for the new Porsche 911 Turbo S. Forced induction simply offers a great advantage and the R8 with its naturally aspirated 5.2 liter V10 can't compete.
Both cars launch off the start and by the 1/2 mile marker the Turbo S is pulling 160.59 miles per hour compared to the R8's 153.47 miles per hour. Unfortunately, we only get a chase view.
Now, with turbos the R8 easily changes the result and puts down insane performance but stock for stock the 911 Turbo S is the faster car and very impressive.